A multivibrator circuit comprising a base bias-supplying circuit for a transistor which is connected with at least one diode in parallel with a resistor for obtaining stable temperature and voltage characteristics. This resistor serves to overcome the problem of the cessation of variations in bias voltage directly proportional to the supply voltage which is caused by the insertion of the diode. Thus it is possible to start and stop oscillation of the multivibrator circuit even when the supply voltage is reduced to a considerably lower voltage.